This invention relates to a paper-sheet dividing apparatus for dividing into stacks, each having a fixed number of paper sheets that are supplied one by one by a conveying path, and transferring the stacks successively to a predetermined position.
Heretofore, apparatus for handling paper sheets, for example, bank notes, data cards and various printed matter have been in practical use. In recent years, demand for a high-speed paper-sheet dividing apparatus has steadily increased.
For example, bank notes are divided into paper sheet stacks having a fixed number of paper sheets. Each stack is bundled with a suitable belt and then kept in storage. As it is inefficient to divide the paper sheets manually into stacks, an automatically operated dividing apparatus is usually used to divide the bank notes into stacks and to bundle them. In such an apparatus, paper sheets supplied one by one can be stacked without stopping the supply of the paper sheets. It is considered that the desired dividing apparatus can continuously pile the paper sheets supplied one by one without interruption, and while the paper sheets are piled as described above, the paper sheets are divided into groups each including a fixed number of paper sheets.
In order to provide a dividing apparatus as described above, a conventional method for changing the travelling direction of paper sheets, called a beat method, has been adopted, wherein each of the paper sheets supplied at a high speed is thrown from the end of the conveying path. The floating paper sheet is then struck by a reciprocal member and dropped to a pile at a predetermined stacking position. The travelling direction changing means has a limited high-speed response, i.e., when the reciprocal member is driven at high speed and with a constant amplitude, the inertial force of the reciprocal member, and consequently the force applied to the travelling direction changing means, is increased. As a result, since operation of the apparatus becomes unstable and the paper sheets are often piled in a bent or disrupted state, it becomes necessary to strengthen the structure of the apparatus increasing the cost.
Accordingly, an apparatus using the beat method is not suitable for high speed operation. In order to eliminate the above-mentioned disadvantages, an apparatus having a blade wheel has been developed. The blade wheel has a plurality of blades extending in the same direction from the vicinity of a shaft of the blade wheel to its periphery. Between every adjacent two blades a space or slot is formed, and each paper sheet supplied from the end of the conveying path is inserted in the slot. The paper sheets in the slots are delivered therefrom and piled in a predetermined position of a transfer means to make stacks each having a fixed number of paper sheets.
Now, assume the number of paper sheets supplied per minute to the blade wheel is N, the period at which successive two paper sheets are supplied is t second, the number of slots formed in the blade wheel is m, the angle between two adjacent blades is .alpha. degree and the rotating speed at which the blade must rotate is n.
Then t, .alpha. and n is expressed as follows. ##EQU1##
For example, when N=1,800 and m=18, then n is 100. This example shows that even if the paper sheets are supplied at a high speed of 1,800 per minute, the blade wheel rotating at a relatively low speed of 100 rpm is able to receive the paper sheets and discharge them at a predetermined position to make a stack.
Heretofore, means for dividing the paper sheets is provided to cooperate with the blade wheel which is effective for dividing the paper sheets into groups containing a fixed number of paper sheets without interrupting the supply of paper sheets. The dividing means is rotated at a higher speed than the blade wheel through a space defined between an end of the conveying means of the paper sheets and the blade wheel. The moving of the dividing means is carried out in the dead time in which a gap of the adjacent two paper sheets passes through the space. Then the dividing means temporarily receives the paper sheets discharged from the blade wheel and delivers them onto a stacking means. The delivering of the paper sheets supported on the dividing member is carried out after the stack of paper sheets which is previously made on the stacking means is transferred to a predetermined position.
When the paper sheets are supplied at high speed, the dead time becomes short and the speed of the dividing means passing the space between the end of the conveying means and the blade wheel must be high. Thus the operation of the dividing means becomes unstable, paper sheets to be supplied to the blade wheel are often blocked and/or jammed by a large inertial force caused by the high speed movement of the dividing means. Furthermore, force applied to the mechanical parts of the paper-sheet dividing apparatus due to inertia is increased and a powerful driving means for the mechanical parts is required resulting in large size and high cost. As mentioned above, even if stacking means with the blade wheel is suited for high speed piling operation, the dividing means to be combined with the stacking means is not suitable for high speed operation. Therefore the apparatus including the stacking means and dividing means as described above is not suitable for high speed operation.